Comorbidity, disease burden and mortality across age groups in a Swedish primary care asthma population: An epidemiological register study (PACEHR)

Asthma is often associated with other diseases. To identify and manage comorbidities is important, as these conditions may increase the disease burden. To describe the prevalence of comorbidities, disease burden and mortality across age groups in a large Swedish primary care real-life asthma population. Observational cohort study of asthma patients, all ages, identified from electronic medical records by ICD-10-CM code, data from 36 primary care centers. Data were linked to national mandatory Swedish health registers. Comorbidities were identified by ICD-10-CM codes and collected from electronic medical records and the National Patient Registers, mortality data from the Cause of Death Register. Exacerbations were defined as hospitalizations due to asthma, and/or emergency visits at hospital and/or prescription claims of oral steroids. In total 33,468 patients (58% women) were included. The most prevalent comorbidities were acute upper respiratory tract infection (53%), rhinitis (25%), acute lower respiratory tract infection (25%), hypertension (21%), anxiety and depression (20%). The comorbidities associated with highest risk for an exacerbation were COPD OR 1.98 (95%CI: 1.80–2.19), nasal polyps OR 1.75 (95%CI: 1.49–2.05) and rhinitis OR 1.52 (95%CI: 1.41–1.63). All-cause mortality was similar to the Swedish population, 1011 deaths per 100,000 person/year compared with 1058 deaths (standardized risk = 0.99 [95%CI:0.95–1.04]). The pulmonary related death rate was greater in the study population versus the Swedish population (122 versus 72 per 100,000person/year). Comorbid disease was frequent in this large real-life asthma population with an impact on exacerbations. To identify and treat comorbidities with impact on asthma outcomes are essential to improve asthma care. •In this Swedish observational asthma study, comorbid disease was common.•The comorbidities associated with highest risk of exacerbations were COPD, nasal polyps and rhinitis.•All-cause mortality in this asthma population was similar to that of the Swedish population.